1. Field of the Invention
The present invention generally relates to a silo door and more particularly a door which can be used in combination with vertical openings in a stave silo, concrete silo and the like in which the door is mounted for pivotal movement and limited sliding movement horizontally so that the door can be self-storing and left in position when unloading a silo using automatic silo unloaders and the like and can be securely latched in closed position when filling the silo thereby eliminating the necessity of lowering and storing the silo doors when unloading a silo and lifting and reinserting the silo doors when the silo is being refilled.
2. Description of the Prior Art
Silo doors to close a vertical opening or openings in a silo wall are generally well known and conventionally, such doors are placed in the vertical opening when the silo is being filled and when the silo is being unloaded, these doors are removed and lowered to ground level and stored in a storage area. As can be appreciated, this requires considerable labor and time. The following U.S. patents disclose various silo door structures and other closures, such as gates and the like, which are relevant to this invention.
U.S. Pat. No. 288,601 PA1 U.S. Pat. No. 964,545 PA1 U.S. Pat. No. 1,126,653 PA1 U.S. Pat. No. 1,130,307 PA1 U.S. Pat. No. 1,162,022 PA1 U.S. Pat. No. 1,642,003 PA1 U.S. Pat. No. 3,997,025 PA1 U.S. Pat. No. 4,118,909 PA1 U.S. Pat. No. 4,271,632
Several of the above patents disclose closure doors for silo structures some of which are removable and some of which are hingedly supported from the silo. However, none of the above patents discloses the specific structure of this invention.